Electrified roads pave science fiction. It is an easy conclusion for many when they think about powering electric vehicles (EV). I remember it was the main feature of the video game Quarantine. Where all the major cities had electric roads powering all the cars. Go off the grid, and it would be a short time before you were stranded. The street gangs would soon be upon you. However, let's talk about science-present.
Toyohashi University of Technology, in Aichi Japan, is currently developing a power system for elevtric vehicles that will be delivered via the road surface. Masahiro Hanazawa, one of the developers, said, "Our approach exploits a pair of tyres, which are always touching a road surface." Which led to placing two steel belts in the tires of the test car that will be in contact with metal plates in the road surface.
Co-developer Takashi Ohira stated that the system could power a typical passenger car In experiments to test how much power is lost in transmission, they put the system on a non-moving vehicle. Ohira explained the result, "Less than 20 per cent of the transmitted power is dissipated in the circuit.. [unfortunately] much higher than regular batteries."
Another downside is the voltage applied to the road. It is in the excess of 50,000 volts. Anything over 40 volts will penetrate human skin causing a shock. Their roads are on the same power levels of tasers. Since the world does not want to pull up their roads to install new infrastructure, it is back to the drawing boards for the Japanese team.
Meanwhile in South Korea, wireless power transfer in roads is being tested by the Korea Advanced Institute of Science and Technology (KAIST). Their concept works off the principles of inductive charging. However, in this case, it is only charging for a fractions of a second.
In a micro-charging scheme, as the EV passes over of the magnetic coils in the road, it makes a quick power transfer connection. Multiply that by the thousands of coils embedded in the road, and a significant amount of power is transferred. The slower the EV moves, the more power is collected.
Even at highway speeds, the roads are able to deliver 30 kW at an average of 80% efficiency. Which is similar to the Japanese team's transfer loss. However, living creatures can touch the charging coils embedded in the road without receiving a shock. On the positive side, the Korean system could be installed now for about $1.5 million USD per mile.
The bus/train using the Korean system is being tested at the KAIST University.
Whether it is one of these two or something else, electric roads are on the way.
Eavesdropper
